1. Field of the Invention
The invention relates to novel flavonoids extracted from an alcohol extract of dehulled adlay seeds and uses thereof.
2. Description of the Related Art
Chronic inflammation contributes to the pathogenesis of a number of diseases that affect a significant part of the human population. Nitric oxide (NO) is an inorganic free radical that is implicated in pathological processes such as chronic and acute inflammation (Salerno, L., Sorrenti, V., Di Giacomo, C., Romeo, G., & Siracusa, M. A. (2002). Progress in the development of selective nitric oxide synthase (NOS) inhibitors. Current Pharmaceutical Design, 8(3), 177-200). NO is produced by the oxidation of L-arginine, catalysed by NO synthase (NOS). In the NOS family, inducible (i)NOS, in particular, is involved in the pathological overproduction of NO, and can be expressed in response to proinflammatory agents such as tumor necrosis factor (TNF)-α and lipopolysaccharide (LPS) in various cell types, including macrophages. Furthermore, activated macrophages cause inflammation, which is mediated by proinflammatory mediators, including TNF-α, interleukin (IL)-6, and NO (Libby, P. (2006). Inflammation and cardiovascular disease mechanisms. The American Journal of Clinical Nutrition, 83(2), 456S-460S). There is growing evidence that systemic inflammation is associated with increased risks of chronic diseases, such as inflammatory bowel disease and cancer (Atreya, R., & Neurath, M. F. (2005). Involvement of IL-6 in the pathogenesis of inflammatory bowel disease and colon cancer. Clinical Reviews in Allergy & Immunology, 28(3), 187-196). Therefore, the application of dietary components, aside from anti-inflammatory drugs, has become a focus of interest. Diets for preventing chronic diseases associated with inflammation were recently proposed as a therapeutic strategy (O'Keefe, J. H., Gheewala, N. M., & O'Keefe, J. O. (2008). Dietary strategies for improving post-prandial glucose, lipids, inflammation, and cardiovascular health. Journal of the American College of Cardiology, 51(3), 249-255).
Adlay (Job's tears, Coix lachryma-jobi L. var. ma-yuen Stapf) is an annual crop, which has long been used in Chinese medicine to treat warts, chapped skin, rheumatism, and neuralgia (Lu, Y., Li, C. S., & Dong, Q. (2008). Chinese herb related molecules of cancer-cell apoptosis: A minireview of progress between Kanglaite injection and related genes. Journal of Experimental & Clinical Cancer Research, 27, 31). It was reported to have various activities, such as anticancer (Lee, M. Y., Lin, H. Y., Cheng, F., Chiang, W., & Kuo, Y. H. (2008). Isolation and characterization of new lactam compounds that inhibit lung and colon cancer cells from adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) bran. Food and Chemical Toxicology, 46(6), 1933-1939), anti-inflammatory (Seo, W. G., Pae, H. O., Chai, K. Y., Yun, Y. G., Kwon, T. H., & Chung, H. T. (2000). Inhibitory effects of methanol extract of seeds of Job's tears (Coix lachryma-jobi L. var. ma-yuen) on nitric oxide and superoxide production in RAW 264.7 macrophages. Immunopharmacology and Immunotoxicology, 22(3), 545-554), and antiallergic effects (Chen, H. J., Shih, C. K., Hsu, H. Y., & Chiang, W. (2010). Mast cell-dependent allergic responses are inhibited by ethanolic extract of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) testa. Journal of Agricultural and Food Chemistry, 58(4), 2596-2601). Various constituents were isolated from adlay, such as anti-inflammatory benzoxazinoids from the roots (Otsuka, H., Hirai, Y., Nagao, T., & Yamasaki, K. (1988). Anti-inflammatory activity of benzoxazinoids from roots of Coix lachryma-jobi var. ma-yuen. Journal of Natural Products, 51(1), 74-79), phenolic compounds with antiallergic properties from the testa (Chen, H. J., Shih, C. K., Hsu, H. Y., & Chiang, W. (2010). Mast cell-dependent allergic responses are inhibited by ethanolic extract of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) testa. Journal of Agricultural and Food Chemistry, 58(4), 2596-2601), cytotoxic lactams from the bran (Lee, M. Y., Lin, H. Y., Cheng, F., Chiang, W., & Kuo, Y. H. (2008). Isolation and characterization of new lactam compounds that inhibit lung and colon cancer cells from adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) bran. Food and Chemical Toxicology, 46(6), 1933-1939), and antioxidative lignans from the hulls (Kuo, C. C., Chiang, W., Liu, G. P., Chien, Y. L., Chang, J. Y., Lee, C. K., et al. (2002). 2,20-Diphenyl-1-picrylhydrazyl radical-scavenging active components from adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) hulls. Journal of Agricultural and Food Chemistry, 50(21), 5850-5855). However, anti-inflammatory and related components of adlay bran, the edible part of adlay, are still unclear.